U.S. shipments of residential gas water heaters increased 9.8 percent in March to 426,072 units, according to the Air Conditioning, Heating and Refrigeration Institute.

The figures are up substantially from the 388,215 units shipped in March 2013.

Residential electric water heater shipments increased 6.7 percent to 395,442 units, up from 370,672 units a year earlier.